Figure 3.

A group of immature aberrant neutrophils emerged in coronavirus-infected mice

(A) Immunohistochemical analysis of the location and expression of S100A8 in the lung tissue of mice infected with SARS-CoV-2 or MHV at 5 dpi. The S100A8⁺ cells in the lungs of mice infected with coronavirus were increased significantly. The red arrows indicate the S100A8⁺ cells. n = 5. Scale bars, 50 μm.

(B) Flow cytometry analysis of neutrophils in lungs from mice infected with SARS-CoV-2 and MHV at 5 dpi. Control group means mice treated with vehicle. Gate P1 shows the conventional neutrophils (CD45⁺CD11b⁺Ly6G^high), and Gate P2 shows the pathologic aberrant neutrophils (CD45⁺CD11b⁺Ly6G^variable). Aberrant neutrophils (P2) in the lungs of mice infected with coronavirus were significantly increased. n = 3.

(C) Flow cytometry analysis of neutrophils in lungs of mice challenged with IAV, EMCV, HSV-1, and LPS at 5 dpi. The results showed that these treatments did not induce an increase in aberrant neutrophils. n = 3.

(D) Flow cytometry analysis of neutrophils in bone marrow from mice infected with SARS-CoV-2 and MHV at 5 dpi. n = 3.

(E) qRT-PCR-analyzed related gene expression of aberrant neutrophils in bone marrow of mice infected with MHV at 5 dpi and identified the differentiated types of aberrant neutrophils. n = 3.

^∗∗∗p < 0.001. Error bars, SD.